xref: /openbmc/linux/drivers/misc/atmel-ssc.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Atmel SSC driver
4  *
5  * Copyright (C) 2007 Atmel Corporation
6  */
7 
8 #include <linux/platform_device.h>
9 #include <linux/list.h>
10 #include <linux/clk.h>
11 #include <linux/err.h>
12 #include <linux/io.h>
13 #include <linux/spinlock.h>
14 #include <linux/atmel-ssc.h>
15 #include <linux/slab.h>
16 #include <linux/module.h>
17 
18 #include <linux/of.h>
19 
20 #include "../../sound/soc/atmel/atmel_ssc_dai.h"
21 
22 /* Serialize access to ssc_list and user count */
23 static DEFINE_SPINLOCK(user_lock);
24 static LIST_HEAD(ssc_list);
25 
26 struct ssc_device *ssc_request(unsigned int ssc_num)
27 {
28 	int ssc_valid = 0;
29 	struct ssc_device *ssc;
30 
31 	spin_lock(&user_lock);
32 	list_for_each_entry(ssc, &ssc_list, list) {
33 		if (ssc->pdev->dev.of_node) {
34 			if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
35 				== ssc_num) {
36 				ssc->pdev->id = ssc_num;
37 				ssc_valid = 1;
38 				break;
39 			}
40 		} else if (ssc->pdev->id == ssc_num) {
41 			ssc_valid = 1;
42 			break;
43 		}
44 	}
45 
46 	if (!ssc_valid) {
47 		spin_unlock(&user_lock);
48 		pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
49 		return ERR_PTR(-ENODEV);
50 	}
51 
52 	if (ssc->user) {
53 		spin_unlock(&user_lock);
54 		dev_dbg(&ssc->pdev->dev, "module busy\n");
55 		return ERR_PTR(-EBUSY);
56 	}
57 	ssc->user++;
58 	spin_unlock(&user_lock);
59 
60 	clk_prepare(ssc->clk);
61 
62 	return ssc;
63 }
64 EXPORT_SYMBOL(ssc_request);
65 
66 void ssc_free(struct ssc_device *ssc)
67 {
68 	bool disable_clk = true;
69 
70 	spin_lock(&user_lock);
71 	if (ssc->user)
72 		ssc->user--;
73 	else {
74 		disable_clk = false;
75 		dev_dbg(&ssc->pdev->dev, "device already free\n");
76 	}
77 	spin_unlock(&user_lock);
78 
79 	if (disable_clk)
80 		clk_unprepare(ssc->clk);
81 }
82 EXPORT_SYMBOL(ssc_free);
83 
84 static struct atmel_ssc_platform_data at91rm9200_config = {
85 	.use_dma = 0,
86 	.has_fslen_ext = 0,
87 };
88 
89 static struct atmel_ssc_platform_data at91sam9rl_config = {
90 	.use_dma = 0,
91 	.has_fslen_ext = 1,
92 };
93 
94 static struct atmel_ssc_platform_data at91sam9g45_config = {
95 	.use_dma = 1,
96 	.has_fslen_ext = 1,
97 };
98 
99 static const struct platform_device_id atmel_ssc_devtypes[] = {
100 	{
101 		.name = "at91rm9200_ssc",
102 		.driver_data = (unsigned long) &at91rm9200_config,
103 	}, {
104 		.name = "at91sam9rl_ssc",
105 		.driver_data = (unsigned long) &at91sam9rl_config,
106 	}, {
107 		.name = "at91sam9g45_ssc",
108 		.driver_data = (unsigned long) &at91sam9g45_config,
109 	}, {
110 		/* sentinel */
111 	}
112 };
113 
114 #ifdef CONFIG_OF
115 static const struct of_device_id atmel_ssc_dt_ids[] = {
116 	{
117 		.compatible = "atmel,at91rm9200-ssc",
118 		.data = &at91rm9200_config,
119 	}, {
120 		.compatible = "atmel,at91sam9rl-ssc",
121 		.data = &at91sam9rl_config,
122 	}, {
123 		.compatible = "atmel,at91sam9g45-ssc",
124 		.data = &at91sam9g45_config,
125 	}, {
126 		/* sentinel */
127 	}
128 };
129 MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
130 #endif
131 
132 static inline const struct atmel_ssc_platform_data *
133 	atmel_ssc_get_driver_data(struct platform_device *pdev)
134 {
135 	if (pdev->dev.of_node) {
136 		const struct of_device_id *match;
137 		match = of_match_node(atmel_ssc_dt_ids, pdev->dev.of_node);
138 		if (match == NULL)
139 			return NULL;
140 		return match->data;
141 	}
142 
143 	return (struct atmel_ssc_platform_data *)
144 		platform_get_device_id(pdev)->driver_data;
145 }
146 
147 #ifdef CONFIG_SND_ATMEL_SOC_SSC
148 static int ssc_sound_dai_probe(struct ssc_device *ssc)
149 {
150 	struct device_node *np = ssc->pdev->dev.of_node;
151 	int ret;
152 	int id;
153 
154 	ssc->sound_dai = false;
155 
156 	if (!of_property_read_bool(np, "#sound-dai-cells"))
157 		return 0;
158 
159 	id = of_alias_get_id(np, "ssc");
160 	if (id < 0)
161 		return id;
162 
163 	ret = atmel_ssc_set_audio(id);
164 	ssc->sound_dai = !ret;
165 
166 	return ret;
167 }
168 
169 static void ssc_sound_dai_remove(struct ssc_device *ssc)
170 {
171 	if (!ssc->sound_dai)
172 		return;
173 
174 	atmel_ssc_put_audio(of_alias_get_id(ssc->pdev->dev.of_node, "ssc"));
175 }
176 #else
177 static inline int ssc_sound_dai_probe(struct ssc_device *ssc)
178 {
179 	if (of_property_read_bool(ssc->pdev->dev.of_node, "#sound-dai-cells"))
180 		return -ENOTSUPP;
181 
182 	return 0;
183 }
184 
185 static inline void ssc_sound_dai_remove(struct ssc_device *ssc)
186 {
187 }
188 #endif
189 
190 static int ssc_probe(struct platform_device *pdev)
191 {
192 	struct resource *regs;
193 	struct ssc_device *ssc;
194 	const struct atmel_ssc_platform_data *plat_dat;
195 
196 	ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
197 	if (!ssc) {
198 		dev_dbg(&pdev->dev, "out of memory\n");
199 		return -ENOMEM;
200 	}
201 
202 	ssc->pdev = pdev;
203 
204 	plat_dat = atmel_ssc_get_driver_data(pdev);
205 	if (!plat_dat)
206 		return -ENODEV;
207 	ssc->pdata = (struct atmel_ssc_platform_data *)plat_dat;
208 
209 	if (pdev->dev.of_node) {
210 		struct device_node *np = pdev->dev.of_node;
211 		ssc->clk_from_rk_pin =
212 			of_property_read_bool(np, "atmel,clk-from-rk-pin");
213 	}
214 
215 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
216 	ssc->regs = devm_ioremap_resource(&pdev->dev, regs);
217 	if (IS_ERR(ssc->regs))
218 		return PTR_ERR(ssc->regs);
219 
220 	ssc->phybase = regs->start;
221 
222 	ssc->clk = devm_clk_get(&pdev->dev, "pclk");
223 	if (IS_ERR(ssc->clk)) {
224 		dev_dbg(&pdev->dev, "no pclk clock defined\n");
225 		return -ENXIO;
226 	}
227 
228 	/* disable all interrupts */
229 	clk_prepare_enable(ssc->clk);
230 	ssc_writel(ssc->regs, IDR, -1);
231 	ssc_readl(ssc->regs, SR);
232 	clk_disable_unprepare(ssc->clk);
233 
234 	ssc->irq = platform_get_irq(pdev, 0);
235 	if (!ssc->irq) {
236 		dev_dbg(&pdev->dev, "could not get irq\n");
237 		return -ENXIO;
238 	}
239 
240 	spin_lock(&user_lock);
241 	list_add_tail(&ssc->list, &ssc_list);
242 	spin_unlock(&user_lock);
243 
244 	platform_set_drvdata(pdev, ssc);
245 
246 	dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
247 			ssc->regs, ssc->irq);
248 
249 	if (ssc_sound_dai_probe(ssc))
250 		dev_err(&pdev->dev, "failed to auto-setup ssc for audio\n");
251 
252 	return 0;
253 }
254 
255 static int ssc_remove(struct platform_device *pdev)
256 {
257 	struct ssc_device *ssc = platform_get_drvdata(pdev);
258 
259 	ssc_sound_dai_remove(ssc);
260 
261 	spin_lock(&user_lock);
262 	list_del(&ssc->list);
263 	spin_unlock(&user_lock);
264 
265 	return 0;
266 }
267 
268 static struct platform_driver ssc_driver = {
269 	.driver		= {
270 		.name		= "ssc",
271 		.of_match_table	= of_match_ptr(atmel_ssc_dt_ids),
272 	},
273 	.id_table	= atmel_ssc_devtypes,
274 	.probe		= ssc_probe,
275 	.remove		= ssc_remove,
276 };
277 module_platform_driver(ssc_driver);
278 
279 MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
280 MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
281 MODULE_LICENSE("GPL");
282 MODULE_ALIAS("platform:ssc");
283